Skip to Content

Why Is My Angelfish Swimming Sideways? (And How to Fix It)

Why Is My Angelfish Swimming Sideways? (And How to Fix It)

This post is written to the author's best knowledge and is not intended to be used in place of veterinary advice. In addtion, this post may contain affiliate links. As an Amazon Associate I earn from qualifying purchases.

Keeping angelfish in your aquarium is great, but you do need to take care of them well to keep them healthy. If you’re kind of new to keeping fish tanks, then you might make a few mistakes along the way.

Thankfully, angelfish are quite hardy, and this means that they’re able to survive pretty well even if you make a few errors. Some problems can be more complicated than others, though.

For example, if you observe your fish tank one day and see that your angelfish is swimming sideways, that’s going to be something to worry about. This definitely isn’t normal behavior, but what is causing it?

Read on to learn why an angelfish might start swimming sideways. You’ll understand the cause as well as what can be done to try to get things back to normal.

Swim Bladder Issues Are to Blame

When a fish starts swimming sideways, it’s going to be because something is wrong with its swim bladder. There are a few different reasons why this might happen, but it usually comes down to abdominal swelling.

If an angelfish gets a swollen belly for some reason, then that is going to put pressure on the swim bladder. It keeps this vital part of the fish from being able to work properly.

A swim bladder that isn’t functioning will make it so that a fish cannot swim normally. This is an organ that controls the buoyancy of the fish.

When that gets impacted, it’s no longer possible for the fish to have good control over how it’s swimming. It might be able to swim a little bit, but it certainly won’t look normal.

You might see that the fish is swimming sideways instead of going forward as normal. There are also instances where the fish will swim completely upside down when it is experiencing swim bladder issues.

It can be very problematic for the fish because it won’t be able to get around reliably when its swim bladder isn’t functioning. This could put the fish in danger of being bullied by other fish, and it’ll probably have a tough time eating as well.

Can This Issue Be Fixed?

Yes, in most situations, this issue should be able to be fixed. Generally, swim bladder problems are caused by a fish becoming constipated.

If the fish has a swollen belly, there’s a good chance that you have been feeding it too much. When a fish overeats, it might wind up becoming constipated.

The swelling belly will wind up causing problems with the swim bladder. It’s a big problem, but it is something that can be fixed by addressing the constipation issues.

Essentially, your fish just needs to poop the excess food out. It’s possible that this might happen naturally, but it’s better to give the fish some assistance.

You want your angelfish to go back to normal as soon as possible. Fixing the constipation issue should be easy if you feed your fish a frozen pea.

Upon eating a frozen pea, the fish should start pooping quite a bit. Eventually, the fish will no longer have a swollen belly, and it’ll be able to start swimming normally once again.

It should be noted that swim bladder issues can be caused by other things, though. Frozen peas will only help to fix swim bladder issues that are caused by constipation.

Bacterial Infections and Swim Bladder Issues

Your fish could also be dealing with issues due to having a bacterial infection. Bacterial infections can cause the fish to have the same problems as constipation.

You’ll need to get rid of the infection to get the fish back to normal in this situation. This could involve treating the fish with antibiotics in severe cases, but you might also need to address issues with the water.

You see, bacterial infections generally happen when there are water parameter issues. You’re supposed to keep the pH balance of the water between 6.8 and 7.8 for safety purposes.

When the parameters are off, ammonia, nitrates, and nitrites can become a problem in the tank. This can stress the fish and cause it to get infected by bacteria.

Remember to test the water regularly to keep this from happening. You can move infected fish to a hospital tank (a separate tank from your main tank) to treat them.

Can the Swim Bladder Become Permanently Damaged?

The swim bladder can become permanently damaged sometimes. This can happen due to injuries, but there could be permanent damage from a really bad infection as well.

In this case, it won’t be totally possible for the fish to get back to normal. It might struggle with swim bladder issues for the rest of its life.

Some angelfish owners will choose to humanely euthanize fish that have these problems. If the fish can get around okay and it’s able to eat fine, it’s okay to keep it alive.

It’s just up to your judgment. If you feel that the fish is having a tough time, then you might think that it would be more humane to euthanize it rather than to keep it alive.

Feeding Advice

You should try to avoid overfeeding your angelfish. It’s important to only feed them as much as is necessary.

Angelfish will always act as if they want food. You’re not supposed to feed them whenever you think they look hungry.

Instead, you should feed them on a regular schedule. An adult angelfish should be fed twice per day.

You’re going to want to feed the angelfish only as much as they can eat in two or three minutes. You’ll eventually get a feel for exactly how much fish food to put in the tank.

If you ever see excess food in the tank, then that’s a sign that you’re giving the fish too much. Remove the food with a scoop instead of leaving it in the tank.

Angelfish eat special fish flakes that are formulated specifically for angelfish. They also eat things such as shrimp pellets.

You can mix up what you’re giving the fish from time to time. Many enthusiasts say that this is the healthiest thing to do for the fish.

If you stick to feeding your angelfish on a schedule, then it’ll be unlikely that you’ll encounter problems with constipation. Keep paying attention to how much you’re feeding the fish so that you won’t have to worry moving forward.